1. Field of the Disclosure
The present disclosure relates in general to systems and methods for sealing between two wellbore members. More specifically, the disclosure relates to an energizing ring that provides a retaining feature to prevent the energizing ring from backing out of an annular seal.
2. Description of the Related Art
In an oil or gas well, the wellhead is generally a tubular member having an axial bore through which other wellbore members may extend. For instance, a casing hanger often extends through the wellhead to support a casing string that extends below the wellhead into the well. The casing hanger can be supported on a load shoulder within the axial bore such that an annular pocket is defined between the casing hanger and the wellhead. An annular sealing assembly may be provided within the annular pocket. The annular sealing assembly can seal the annular pocket to contain internal well pressure and prevent well fluids from escaping out of the well. During wellbore operations, the wellhead can be subjected to high pressure. This pressure can exert upward force on the casing hanger. Significant force can urge the casing hanger upward from its position in the wellhead housing. The annular sealing assembly can also act as a lockdown device to help resist movement of the hanger relative to the wellhead that is caused by, for example, the annulus pressure or thermal growth.
One type of annular sealing assembly has a seal body for creating a metal-to-metal seal with a generally “U” shaped cross-section defined by inner and outer legs. The inner and outer legs are radially separated from one another at one end and coupled to one another at their opposite ends. In alternate embodiments, the seal body can be generally “H” shaped or generally upside down “U” shaped. An energizing ring is pressed into an annular clearance between the inner and outer legs to force the legs apart, and thereby force the legs into sealing engagement with adjacent wellbore members, such as the wellhead and casing hanger. The energizing ring can be a solid wedge-shaped member with tapered surfaces. However, the shape of the tapered surfaces on the energizing ring means that any upward movement of the energizing ring can allow the inner and outer legs ring to move towards each other, weakening the lockdown and compromising the seal.